My blog, on my time working in professional stage management, puppetry, working as a television 'walk-on/extra', my heart attack in 2006, working in care, life as a child living in the countryside and life in general.
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Wednesday, November 14, 2012
Beta blockers don't work, new study finds
I came across the following article on the New Scientist website. I reproduce it below. As I am myself on beta blockers since having a heart attack (I am on Bisoprolol Fumarate.) so I am now somewhat concerned that these types of drugs don't actually do what they are supposed to do, or so the newest research would suggest. The article is dated 12th November 2012, so it is pretty recent. The article is fairly complex, but it is worth reading it in full to understand what the content of the report says.
'Beta blockers are busted- What Happens Next?'
'They have treated heart disease for 40 years but it now seems that beta blockers don't work. What went wrong?'
'IT IS very rare for new evidence to question
or even negate the utility of a well-established class of drugs. But after four
decades as a standard therapy for heart disease and high blood pressure, it
looks like this fate will befall beta blockers. Two major studies published
within about a week of each other suggest that the drugs do not work for these
conditions. This is a big surprise, with big implications.
The first beta blocker, Inderal, was launched
in 1964 by Imperial Chemical Industries for treatment of angina. This drug has
been hailed as one of great medical advances of the 20th century. Its inventor,
James Black, was awarded the Nobel prize in medicine in 1988.'
'The 20 or so beta blockers now on the market
are very widely used - almost 200 million prescriptions were written for them
in the US in 2010. They are standard issue for most people with heart disease
or high blood pressure. This may now change.'
'A large study published last month in The
Journal of the American Medical Association found
that beta blockers did not prolong the lives of patients - a revelation that
must have left many cardiologists shaking their. (JAMA, vol 308, p 1340.)'
'The researchers followed almost 45,000 heart
patients over three-and-a-half years and found that beta blockers did not
reduce the risk of heart attacks, deaths from heart attacks, or stroke.'
'While this is not definitive, it's pretty
damning, especially when another study - published just days earlier - found
pretty much the same thing.( Journal of the American Geriatrics Society, vol 60. p1854.)'
'The goal of this second study was to examine
the effect of drug compliance on death rates in patients who had had heart
attacks. About half of patients complied with their drug regimen.
Unsurprisingly, these people were nearly 30 per cent less likely to die than
those who did not comply.'
'This was to be expected, but there was one big
surprise. While the result held for the standard classes of heart drugs -
statins, anticoagulants and antihypertensives - it did not for beta blockers.
Regardless of whether or not patients stuck to their regimen, their risk of
dying was the same. Taken together with the JAMA
study, it becomes very reasonable to question the benefit of beta blockers for
treating these conditions.'
'To understand what is going on, consider how
they work. Like many drugs, beta blockers target receptors embedded in the
surface of cells. Receptors are "molecular switches" - when a
specific molecule binds to them, they change shape and send a signal to the
cell to perform a certain function. Beta blockers target beta receptors, which
respond to the "fight or flight" hormones adrenalin and noradrenalin.'
'In humans, there are two principle types of
beta-receptor - beta-1, primarily found in the heart, and beta-2,
located at multiple sites, including the smooth-muscle cells of the
bronchial tubes and in veins.'
'When adrenalin and noradrenalin bind
to beta-1 receptors, they signal the heart to beat faster and pump
harder. Binding to beta-2 receptors causes smooth muscle relaxation,
especially in the airways, explaining why beta-2 activators are used as
'Beta blockers bind to both types of
receptor, but do not activate the cellular response. This blocks
adrenalin and noradrenalin from reaching their target and activating the
response. By preventing the normal hormone-receptor interaction, the
beta blockers slow the heart and cause it to pump less forcefully,
lowering blood pressure.'
'The premise of beta-blocker therapy
has been that giving the heart a rest will diminish the frequency of
heart attacks. In the light of the two new studies, it is clearly time
to question this.
Which raises the question: why has it
taken so long to find out? It is worth noting at this point that this is
not yet another case of a drug entering the market only to be withdrawn
later because of lack of efficacy or even adverse reactions which could
have been noticed with longer or larger trials. It is simply a new
medical revelation. The authors of the JAMA paper provide a reasonable explanation of the conflict between their results and earlier studies.'
'The key word is "earlier". Most
clinical trials on beta blockers took place before reperfusion therapy
became standard treatment following heart attacks. Reperfusion involves
opening the blocked artery by surgery or pharmaceuticals, and has been
shown to significantly reduce damage to the heart.
Damaged hearts are more prone to fatal
irregular beats, and beta blockers are useful in controlling this. But
with the advent of reperfusion therapy, people who survived heart
attacks suffered less cardiac damage, so the frequency of fatal
arrhythmias was lower. Put simply, the beta blocker effect was
significant before the advent of this improved treatment, but the
beneficial effect has since disappeared.'
'Additionally, newer and better drugs
such as anticoagulants, statins and antihypertensives are now routinely
used in heart disease. These more effective therapies swamp any smaller
benefit that the beta blockers might provide, minimising any measurable
'What comes next is impossible to
predict, but we may well be seeing a rare case of medical wisdom being
overturned almost overnight. Beta blockers are not dangerous and have
been in use for such a long time that it is unlikely that we will see an
immediate cessation. But these results are hard to ignore, and
cardiologists will be paying careful attention.'